package com.lw.reflection;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * @author LW
 * @2020/9/23 17:51
 */
//分析性能问题
public class Test09 {

    public static void main(String[] args) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
        test01();
        test02();
        test03();
    }

    //普通方式调用
    public static void test01(){
        User user = new User();

        long startTime = System.currentTimeMillis();

        for (int i = 0; i < 1000000000; i++) {
            user.getName();
        }
        
        long endTime = System.currentTimeMillis();
        System.out.println("普通方式执行10亿次："+(endTime-startTime)+"ms");
    }

    //反射方式调用
    public static void test02() throws InvocationTargetException, IllegalAccessException, NoSuchMethodException {
        User user = new User();
        Class c1 = user.getClass();

        Method getName = c1.getDeclaredMethod("getName", null);
        long startTime = System.currentTimeMillis();

        for (int i = 0; i < 1000000000; i++) {
            getName.invoke(user,null);//调用方法，（调用对象，传递参数）
        }

        long endTime = System.currentTimeMillis();
        System.out.println("反射方式执行10亿次："+(endTime-startTime)+"ms");
    }

    //反射方式调用   关闭检测
    public static void test03() throws InvocationTargetException, IllegalAccessException, NoSuchMethodException {
        User user = new User();
        Class c1 = user.getClass();

        Method getName = c1.getDeclaredMethod("getName", null);
        getName.setAccessible(true);//关闭检测
        long startTime = System.currentTimeMillis();

        for (int i = 0; i < 1000000000; i++) {
            getName.invoke(user,null);
        }

        long endTime = System.currentTimeMillis();
        System.out.println("反射方式关闭检测执行10亿次："+(endTime-startTime)+"ms");
    }
}
